Indeed, 100% compatibility can be achieved by using Parallels Desktop / VMWare Fusion / VirtualBox / Apple Boot Camp instead.
Are you going to provide me with a FREE copy of Windows? There is no way I would ever pay for an OS that has spawned an entire industry to try and get around viruses etc that Microsoft is powerless to stop. The ONLY reason I use CrossOver for KVS is that there I don't have to worry about Windows vulnerabilities.
How about with the money you are making from Macintosh users that you employ someone who can write OS X code to develop a Mac specific product.